The present invention relates to directing a gas flow in a substrate processing chamber.
In the fabrication of active and passive electronic devices, semiconductor, dielectric, and conductor materials, such as for example, polysilicon, silicon dioxide, aluminum or tungsten silicide, are formed on a substrate by, for example, chemical vapor deposition (CVD), physical vapor deposition (PVD), oxidation and nitridation processes. In CVD processes, a reactive gas is used to deposit material on the substrate, and in PVD processes, a target is sputtered to deposit material on the substrate. In oxidation and nitridation processes, an oxide or nitride material, for example, silicon dioxide or silicon nitride, respectively, is formed on the substrate by exposing the substrate to a suitable gaseous environment. In subsequent processes, a patterned mask of photoresist or hard mask is formed on the substrate by photolithographic methods, and the exposed portions of the substrate are etched by an energized gas to form patterns of gates, vias, contact holes or interconnect lines.
In such processes, process residues may deposit on the surfaces of walls and other components in the chamber. The composition of the process residues may depend upon the composition of the process gas, the material being deposited or etched, and the composition of material on the substrate. These residues have to be periodically cleaned off from the chamber surfaces to reduce or prevent contamination of the substrate. The chamber may be cleaned by a wet-cleaning process in which the chamber is shut down and an operator scrubs the chamber walls with an acid or solvent. However, the chamber downtime that occurs during the wet cleaning process is undesirable. Also, the wet cleaning process often varies in quality and thoroughness from session to session because it is manually performed, and this may affect the processes conducted in the chamber.
The chamber may also be cleaned by a dry-cleaning process in which plasma or microwave-activated cleaning gas is provided in the chamber. However, the cleaning gas may be slow at cleaning-off certain types of residue deposits, for example, those which are relatively thick or which have a chemical composition that is hard to clean. As one example, in CVD deposition chambers, a thicker residue deposit may be formed at regions of the chamber which are near the gas inlet nozzles. It is more difficult to clean off the thicker residue deposits without relatively long chamber cleaning downtime, erosion of exposed chamber surfaces at other portions of the chamber, or the use of highly erosive gas chemistries.
Thus, it is desirable to increase the processing efficiency of a gas in a substrate processing chamber, for example, the cleaning efficiency of a cleaning gas. It is further desirable to uniformly remove residues having variable thickness or non-uniform chemical compositions without eroding underlying chamber surfaces.
The present invention provides an apparatus and method useful in the processing of a substrate in a chamber, for example in cleaning the chamber.
One aspect of the present invention comprises a substrate processing chamber comprising a first gas distributor adapted to provide a process gas into the chamber to process the substrate, a second gas distributor adapted to provide a cleaning gas into the chamber to clean the chamber, and an exhaust to exhaust the process and cleaning gas from the chamber.
In another aspect, a substrate processing chamber comprises first means for providing a process gas into the chamber to process the substrate, second means for providing a cleaning gas into the chamber to clean the chamber, and an exhaust to exhaust the process and cleaning gas from the chamber.
In yet another aspect, a substrate fabrication method comprises processing one or more substrates by (i) placing a substrate in a process zone, (ii) providing a process gas at a first region of the process zone to process the substrate, (iii) exhausting the process gas, (iv) removing the substrate, and (v) optionally, repeating steps (i) through (iv); and providing a cleaning gas at a second region of the process zone to clean a surface therein.
In a further aspect, the present invention comprises an apparatus capable of depositing material on a substrate, the apparatus comprising a deposition chamber having a support to support a substrate, a first gas distributor to provide a deposition gas to the deposition chamber, a plasma generator to form a plasma from the deposition gas to deposit material on the substrate, and an exhaust to exhaust the deposition gas from the deposition chamber; a remote chamber adapted to energize a cleaning gas; and a second gas distributor connecting the remote chamber to the deposition chamber, the second gas distributor adapted to direct a flow of the energized cleaning gas to a region of, or across a surface in, the deposition chamber.
In yet another aspect, a substrate processing apparatus comprises a chamber comprising a support to support a substrate, a first gas distributor to provide a process gas to the chamber, a plasma generator to form a plasma from the process gas to deposit material on the substrate, and an exhaust to exhaust the process gas from the chamber; a remote chamber adapted to energize a cleaning gas; and a second gas distributor connecting the remote chamber to the chamber to introduce the energized cleaning gas at a location that is distal from the exhaust.
In another aspect, a substrate processing method comprises processing one or more substrates by (i) placing a substrate in a process zone, (ii) providing a process gas into the process zone to process the substrate, (iii) exhausting the process gas via an exhaust zone, (iv) removing the substrate from the process zone, and (v) optionally, repeating steps (i) through (iv); and introducing a cleaning gas into the process zone at a location that is distal from the exhaust zone.
In another aspect the present invention comprises a gas distributor capable of distributing a gas in a substrate processing chamber, the gas distributor comprising one or more gas outlets adapted to direct gas preferentially across a surface of the chamber.